Disclosed herein are toner compositions having toner particles comprising a polyester-wax resin, wherein the polyester-wax resin includes a wax that is chemically incorporated into the main chain of the polyester resin.
There is a need for toner particles with improved release properties, such that toner compositions having the toner particles can be used in oil-less fusing fixtures or with fusers requiring very little oil as a release agent. In known methods for making toner particles, wax is typically separately incorporated into the toner formulation during the emulsion aggregation process for use in these types of fixtures/fusers. However, in some development systems, the free wax particles that may be generated on a toner particle's surface may adversely affect wires in the xerographic device.
Specifically, in some development systems, where toner is developed from a donor roll to the imaging member, it is necessary to apply a high voltage DC and a high AC voltage, which can be as high as about 1000 V each, to a fine wire of about 150 microns or less, which is stretched across the length of the donor roll, to detach the toner from the donor roll to enable the toner to be developed to the imaging member. This wire must be kept clean of contamination, which is any material which becomes stuck on the wire and thus builds up on the wire surface. This contamination will result in poor image quality, such as streaks in the process direction, as areas of the wire that are contaminated provide poor development, which is evident as streaks of lower toner image density on the imaging member and on the final image on the paper. Also, once a substantial portion of the wire becomes severely contaminated, the overall development of toner also is reduced. This results eventually in images that are too light in image density. It is known that free wax, that is, wax that is not incorporated within the toner, can be attracted to the wire out of the developer, and accumulate on the wire where it builds up with time. The result is streaks on the prints and reduced development as the machine continues to print. This problem will not go away without removing and replacing the wires, which is not a desirable solution. Thus, it is still desired to produce toner particles suitable for use with oil-less fusing fixtures, without adversely affecting any component of a xerographic device.
The toner compositions having toner particles comprising a polyester-wax resin as described herein are capable of use in an oil-less fusing fixture, without adversely affecting the xerographic device.